Two forgeries exist; for example Fournier offers these 5 stamps in tête-bêche for 1 Swiss Franc as first choice forgeries in his 1914 pricelist (however, they do not appear in 'the Fournier album of philatelic forgeries'). There are also reprint forgeries made in Spain (Barcelona), these were made from the genuine plates that were probably stolen, also with tête-bêche stamps. Any tête-bêche stamps are therefore highly suspicious.

Later issues

Some of the later issues were printed on so-called Winchester security paper. A pattern of circles becomes visible once the stamps have been in contact with water. The design of the stamp almost becomes invisible.